Embryo Time in Culture Determines IVF Baby's Birth Weight

Birth weight of a baby born via in vitro fertilization (IVF) depends on the length of time the embryo spends in culture, before being placed in the womb, a new study from Finland says.

In vitro fertilization (IVF) is the process of manually combining an egg and sperm in a laboratory. IVF is one of the artificial methods known as Assisted Reproductive Technology (ART). ART is adopted by people who experience difficulties in conceiving naturally. ART has been prevalent in US from 1981 and each year, over 1 percent of American infants are conceived through ART.

For the study, a team of researchers from the University of Helsinki examined the factors that influence an IVF baby's birth weight. For reaching a conclusion, they examined more than 1000 singleton babies, born via IVF method, Live Science reported.

Researchers recorded the weight of babies at birth. They found embryos that had spent between five and six days in culture bigger in size (19 percent) at birth compared to embryos cultured between two and three days.

According to the researchers, both overweight and low birth weight pose problems for children's health.

Children born small for gestational age are at a higher risk of developing learning problems, intellectual disabilities, cerebral palsy and vision/hearing loss. A birth weight less than 2,500 grams (five pounds and eight ounces) is considered to be a low birth weight. In the United States, about one in every 12 babies is born with a low birth weight and it is one of the leading causes of neonatal mortality or death before 28 days of age in the country.

On the other hand, children who are large at birth are more likely to be overweight during adolescence, escalating their risks of becoming obese in adulthood.

Results of the study have been published online in Human Reproduction.